This disclosure relates generally to microelectromechanical systems (MEMS), and in particular but not exclusively, relates to MEMS devices to improve fluid flow, such for the enhancement of thermal performance of heat sinks.
Many devices generate heat when they operate. For instance, as computer processors increase in speed of operation, the amount of heat generated by the processors increases. To prevent such devices from overheating and for reliability purposes, the generated heat must be dissipated or otherwise taken away from the devices.
A common technique to dissipate heat is to attach heat sinks to the devices. Heat sinks are typically made from copper or other suitable heat-conductive material, and often include xe2x80x9cfinsxe2x80x9d to increase its surface area for heat dissipation. In operation, a heat sink conducts heat away from a device and dissipates the heat through its fins, sometimes with the aid of a fan that blows across the fins.
In performing this heat transfer, two types of thermal resistances are encountered. Conduction resistance is encountered when heat is transferred between solid materials. In this case, use of a good heat conductive material, such as copper for the heat sink, allows for more efficient heat transfer away from the device.
Convection resistance is encountered when transferring heat from a solid material, such as from surfaces of the fins of the heat sink, to the surrounding fluid (e.g., the surrounding fluid is air in this instance). A thick boundary layer forms along each fin, thereby reducing the effectiveness of air cooling. That is, the thickness of the boundary layer decreases the heat transfer surface""s (e.g., the fins"") efficiency to reject heat to the surrounding fluid. Moreover, the use of an additional fan to aid in heat dissipation from the heat sink further increases inefficiency of the overall system.